The Blues, who got to the Western Conference Second Round thanks to puck possession, smart passing and a solid power play, were lacking in those areas when they lost 2-1 to the Dallas Stars in Game 5 on Friday.
St. Louis now trails the series and faces elimination with Game 6 at Dallas on Sunday (3 p.m. ET; NBC, SN, TVAS).
RELATED: [Complete Blues vs. Stars series coverage]
"I mean, there were ups and downs all game," Blues coach Craig Berube said. "There were real good stretches where we were good, physical, on top of things, getting some looks. But there were other times when we were a little bit sloppy, for sure, with our puck play that caused them to get opportunities."
The Blues had 15 giveaways, some of which led to breakaway chances for the Stars. Goalie Jordan Binnington kept most of those mistakes from becoming goals, saving 25 of the 27 shots he faced.
Jason Spezza scored 2:42 into the first period to give Dallas a 1-0 lead. Esa Lindell scored his first goal of the Stanley Cup Playoffs when his backhand went off Blues defenseman Jay Bouwmeester for a 2-0 lead at 6:13 of the second period.
But the bigger issue for the Blues was their power play. It was 0-for-4 with five shots on goal. Entering Game 5, the Blues had scored on 22.6 percent of their power-play opportunities (7-for-31) this postseason.